The present disclosure is generally related to toners comprising distilled or fractionated waxes, hereinafter referred to as wax or waxes, and more specifically, to toners made by emulsion aggregation (EA) and coalescence processes. The waxes herein are crystalline waxes, and have a degree of crystallization. The resulting toners can be selected for known electrophotographic, electrostatographic, xerographic, and like imaging processes, including copying, printing, faxing, scanning, and like machines, and including digital, image-on-image, color, lithography, and like processes.
In reprographic technologies, such as xerographic and ionographic devices, it is desired to provide toners with high gloss. It is also desired to provide toners that can be used in an oil-less environment, and at low minimum fusing temperatures. It is further desired to provide toners that can be used in high-speed printing and/or copying and the like, machines.
Toners in accordance with embodiments herein, provide desired fusing characteristics including, for example, release characteristics such as a stripping force of less than about 30 to less than about 5 grams of force; blocking characteristics such as a high blocking temperature of about 45° C. to about 65° C.; document offset characteristics such as a document offset of about 2.0 to about 5.0; vinyl offset characteristics such as a vinyl offset of about 3.0 to about 5.0; and triboelectrical charging characteristics. Further, toners in embodiments herein, enable the use of lower minimum imaging fusing temperatures, such as from about 120° C. to about 170° C., enable high speed printing such as for machines running at greater than about 35 pages per minute. Further, the present toners, in embodiments, enable high image gloss, such as in an oil-less fuser system, while still retaining a high blocking temperature, high image gloss comprising of for example from about 30 to about 60 gloss units (GGU) as measured by the Gardner Gloss metering unit; for example on a coated paper, such as Xerox 120 gsm Digital Coated Gloss papers.
Illustrated in U.S. Pat. No. 5,994,020, the disclosure of which is totally incorporated herein by reference, are toner preparation processes, and more specifically, a process for the preparation of toner comprising: (i) preparing, or providing a colorant dispersion; (ii) preparing, or providing a functionalized wax dispersion comprised of a functionalized wax contained in a dispersant mixture comprised of a nonionic surfactant, an ionic surfactant, or mixtures thereof; (iii) shearing the resulting mixture of the functionalized wax dispersion (ii) and the colorant dispersion (i) with a latex or emulsion blend comprised of resin contained in a mixture of an anionic surfactant and a nonionic surfactant; (iv) heating the resulting sheared blend of (iii) below about the glass transition temperature (Tg) of the resin particles; (v) optionally adding additional anionic surfactant to the resulting aggregated suspension of (iv) to prevent, or minimize additional particle growth of the resulting electrostatically bound toner size aggregates during coalescence (iv);heating the resulting mixture of (v) above about the Tg of the resin; and optionally, (vii) separating the toner particles.
Emulsion/aggregation/coalescence processes for the preparation of toners are illustrated in a number of Xerox patents, the disclosures of each of which are totally incorporated herein by reference, such as U.S. Pat. Nos. 5,290,654, 5,278,020, 5,308,734, 5,370,963, 5,344,738, 5,403,693, 5,418,108, 5,364,729, and 5,346,797; and also of interest may be U.S. Pat. Nos. 5,348,832; 5,405,728; 5,366,841; 5,496,676; 5,527,658; 5,585,215; 5,650,255; 5,650,256; 5,501,935; 5,723,253; 5,744,520; 5,763,133; 5,766,818; 5,747,215; 5,827,633; 5,853,944; 5,804,349; 5,840,462; 5,869,215; 5,863,698; 5,902,710; 5,910,387; 5,916,725; 5,919,595; 5,925,488; 5,977,210; 5,994,020; 6,020,101; 6,130,021; 6,120,967 and 6,628,102.
In addition, the following U.S. patents relate to emulsion aggregation processes of forming toner compositions, the disclosures of each of which are totally incorporated herein by reference.
U.S. Pat. No. 5,922,501 describes a process for the preparation of toner comprising blending an aqueous colorant dispersion and a latex resin emulsion, and which latex resin is generated from a dimeric acrylic acid, an oligomer acrylic acid, or mixtures thereof and a monomer; heating the resulting mixture at a temperature about equal, or below about the glass transition temperature (Tg) of the latex resin to form aggregates; heating the resulting aggregates at a temperature about equal to, or above about the Tg of the latex resin to effect coalescence and fusing of the aggregates; and optionally isolating the toner product, washing, and drying.
U.S. Pat. No. 5,482,812 describes a process for the preparation of toner compositions or toner particles comprising (i) providing an aqueous pigment dispersion comprised of a pigment, an ionic surfactant, and optionally a charge control agent; (ii) providing a wax dispersion comprised of wax, a dispersant comprised of nonionic surfactant, ionic surfactant or mixtures thereof; (iii) shearing a mixture of the wax dispersion and the pigment dispersion with a latex or emulsion blend comprised of resin, a counterionic surfactant with a charge polarity of opposite sign to that of said ionic surfactant, and a nonionic surfactant; (iv) heating the above sheared blend below about the glass transition temperature (Tg) of the resin to form electrostatically bound toner size aggregates with a narrow particle size distribution; (v) adding additional ionic surfactant to the aggregated suspension of (iv) to ensure that no, or minimal additional particle growth of the electrostatically bound toner size aggregates occurs on further increasing the temperature to coalesce the aggregates into toner particles (vi); (vi) heating the mixture of (v) with bound aggregates above about or at the Tg of the resin; and optionally (vii) separating the toner particles from the aqueous slurry by filtration and thereafter optionally washing.
U.S. Pat. No. 5,622,806 describes a process, for example, for the preparation of toner compositions with controlled particle size comprising (i) preparing a pigment dispersion in water, which dispersion is comprised of a pigment, an ionic surfactant in amounts of from about 0.5 to about 10 percent by weight to water, and an optional charge control agent; (ii) shearing the pigment dispersion with a latex mixture comprised of a counterionic surfactant with a charge polarity of opposite sign to that of the ionic surfactant, a nonionic surfactant, and resin particles, thereby causing a flocculation or heterocoagulation of the formed particles of pigment, resin, and charge control agent; and (iii) stirring.
U.S. Patent Application Publication 2004/0130054 A1 discloses waxes used in inks and toners. The waxes have a melting point of 50 to 120° C., and a melting range of 5 to about 65° C.